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June 3, 1930. BERDON 1,762,114

LIQUID FUEL PUMP Original Filed April 12, 1927 ;A r. g $45.2.

r 1 WW 6 U 10 l 11 9 f/ f I 2 i 30 k j INVENTOR. 4 29 flaw/1J6 5523MPatented June 3, 1930 UNITED STATES PATENT, OFFICE Anna E. BER-DON, OFDETROIT, MICHIGAN, ASSIGNOB TO A. SPARK PLUG COMPANY,

OI FLINT, MICHIGAN, A COMPANY OF MICHIGAN LIQUID-FUEL PUMP Originalapplication flied April 18, 1927, Serial No. 188,103. Divided and thisapplication filed February 4, 1928. Serial No. 251,802.

This invention relates to fluid pumps and particularly to pumps forsupplying liquid el to internal combustion engines and other fuelconsuming and receiving devices. The present application is a divisionof application 183,103, issued asPatent 1,647,768, November 1st, 1927. r

The special objects of this invention are to provide a fuel pump,capableof delivering the liquid at an appreciable pressure, which will beself-regulating in its operation and which will be of relatively simple,inexpensive, durable construction.

These and further desirable objects are attained by certain novelfeatures of construction, combinations and relations of parts ashereinafter described, illustrated and broadly claimed.

The drawing accom anying and forming part of the specificati illustratesa practical embodiment of the invention, this structure exemplifying,however, rather than limiting the precise orm in which the invention mabe embodied. as igure 1 is a vertical sectional view of the Figure 2 1sa broken part sectional view taken at the left of Figure 1, thesectional portion as on line 22 of that figure. I so The body of thepump shown comprises a base structure 3 havin a valved inlet 4 and avalved outlet 5, said iase carrying a pump cylinder 6 with which thevalved inletand outlet ports communicate by passages 7 8.

The pumping element is made up of two relativel movable portions, apiston 9 and a surroun ing sleeve 10 having an annular lower face 11exposed to the pressure in the 1 pump chamber. This main andsupplementary piston have close fitting oversliding enagement, onerelative to the other and with- 111 the cyhnder, piston rings such asindicated at 12 being usually provided to effect a pro er seal betweenthese parts.

tuated by a screw rod 13 engaged atits outer end with a screw seat 14 inthe yoke 15 which is ivoted at 16 to an intermediate portion of ever 17,which lever has a fulcrum 18 at 80 one end supported from the pump baseand e main piston is shown as positively achas a fork'19 at its oppositeend engaged by a cam or eccentric 20 on an actuating shaft 'Assuming themain piston to be the positively actuated piston, the sleeve orsupplementary or auxiliary piston 10 has an impositive movement, thestroke of which is governed by the pressure in the pump chamber. Thisimpositive connection may be provided by the springs 22, 23, surroundingthe pump rod 13 and bearing against Washers 31 32, which engage theouter and inner faces of the head of the sleeve piston. The washers 31,32 are positioned by bearing against a stop collar 24 fixed on the pumprod and the tensions of the two springs are independentlfy adjustable bynuts 25, 26 on the rod which orm the outer abutments for the springs.

The head or top portion of the outer piston element is shown as leftopen as by providing perforations 27 therein for escape and entrance ofair during relative movements of the piston parts 9 and 10 and toprovide ac Bass for adjustment of the lower abutment nut The valves forthe inlet and discharge ports may be constructed after the manner shownin Fi re 2, consisting in each instance simply o a light disc 28 held toits seat 29 by a spring 30 the passages 7 and 8 of the inlet and outletbeing arranged in back of and in front of the valve respectively so thatthe valves will properly control the inlet and outlet functions.

The recipiocation of the main or central piston mem r is positive andconstant while that of the supplementary piston member is impositive andvariable in accordance with pressure in the pump chamber. The tension ofthe springs 22, 23 governs the extent to which the sleeve piston willfollow the main piston and the pressure at which it will assert its owninde endence of movement. These springs may e adjusted withoutdisassembly of any of the parts and hence the action ofthe pump may beaccurately regulated or altered to suit existing conditions at any time.Usually the sleeve piston may be tensioned to travel in unison with themain piston while conditions are normal so as to get the benefit of thefull combined pumpin area of both piston elements. Then, under a normalconditions, with change of pressure from the normal, the piston elementswill not travel in unison, but one will yield relative to the other toaccommodate for the change in pressure.

With this construction it is possible that one piston element may movein a direction opposite to the direction of movement of the other part.The construction described enables the pump to supply the liquid at adesired pressure, to regulate itself automatically and to accommodateitself to extreme conditions such as the closing of the inlet or of theoutlet. On the closing of the inlet, the sleeve piston, under externalpressure, might remain stationary or actually travel inwardly while thepositively actuated piston is on its outward stroke. The conditionswould be reversed with the closing of the outlet and then the sleevepiston might remain stationary or actually move-outwardly while thepositive piston is travelling inwardly. The osition where the stopcollar 24 is secure on the pump rod fixes the normal relation of thesleeve piston to the inner iston and the adjustment of the pump rod inthe screw seat 14 determines the innermost position of the two pistonsand hence the minimum clearance in the pump chamber. By variousadjustments of these parts and by adjustment of the tension of springs22, 23, the pum may be made to perform to suit many di erentrequirements. The abutment washers 31, 32 for the inner ends of thesprings are clear of the pump rod 13 so that they may freely leave theabutment or posi tioning collar 24 under abnormal pressure conditions.When the pump rod 13 is adjusted in the screw seat 14 to predeterminethe terminus of the unitary movement of the pistons, the same may besecured in the desired adjustment by the lock nut 33.

What is claimed is:

1. In a pump of the character disclosed, a pump cylinder having valvedinlet and outlet ports, a sleeve piston operating in the cylinder and apiston operable in said sleeve piston, said pistons having piston facesexposed in the chamber of the cylinder and ointly coo erative to providea maximum pumping e ect and actuating means for said pistons operable toenable movement of said pistons relative to each other in oppositedirections to reduce the resultant pumping effects of said pistons inboth directions of the pumping strokes.

2. In a pump of the character disclosed, a pump cylinder having valvedinlet and outlet ports, a sleeve piston operating in the cylinder, apiston operative in said sleeve piston, both pistons having pum facesexposed to the chamber of the cylin er, a positive actuating connectionto one of said pistons and two opposed yielding impositive actuatingconnections to the other piston enabling said latter piston to follow ineither direction to a greater or less extent the pumping strokes of thefirst piston.

3. A pump comprising a pump cylinder having valved inlet and outletports, a sleeve piston provided with a head and operating in saidcylinder and having an exposed annular piston face, a piston operativein said sleeve piston, a constant stroke connecting means to one of saidpistons, and resilient connecting means to the other of said pistons,oneof said connecting means comprising springs which act oppositely uponsaid head, to permit one of said pistons to lag relatively to the other.

4. A pump comprising a pump cylinder having valved inlet and outletports, telescopically related pistons working in said cylinder, meansincluding a plurality of oppositely acting springs for effecting aunitary and a differential operation of said pistons and means forvariably predetermining the terminus of the stroke in the unitarymovement of the two pistons.

5. A pump comprising a pump cylinder having valved inlet and outletports, pistons operating in telescopic relation in said cylinder, meansfor effecting a combined unitary and differential action of the pistonsin the cylinder, including resilient coupling means between the pistons,said coupling means being adjustable in opposite directions topredetermine either way the initial positions of the pistons relative toeach other.

6. A pump comprising a pump cylinder having valved inlet and outletports, a sleeve piston operating in the cylinder, a piston operating insaid sleeve piston, a pump rod connected with said latter piston, acollar on said rod, loose washers on the rod at opposite sides of saidcollar and having engagement with the sleeve piston, springs surroundingthe rod and hearing at their inner ends on said Washers, abutments onthe rod for the outer ends of said springs and means for reciprocatingthe pump rod.

7. A pump comprising a pump cylinder having valved inlet and outlet, asleeve piston operating in the cylinder, :1. piston operating in saidsleeve piston, a pump rod having an adjustable positive drive connectionwith the latter piston and oppositely acting spring connections from thepump rod to the sleeve piston yieldable in the opposite directions ofmovement of the pump rod to enable the sleeve piston to lag behind theinside piston in the pumping action either way.

8. A pump comprising: a pump cylinder having a valved inlet and a valvedoutlet; a sleeve piston operating in the cylinder; an additional pistonoperating within said sleeve piston; a pump rod having an adjustablepositive drive connection with one of said pistons; and oppositelyacting spring connections therefrom to the other iston,said springconnections being yieldab e in opposite directions of movement of thepump rod to enable the last-mentioned piston to lag behind thepositively driven piston and the said pump rod.

In testimony whereof I aflix my signature.

ALBERT E. BERDON.

